1. Field of the Invention
The present invention relates to the delivery of a stent or conduit and other devices into the myocardium of a patient, and more particularly, to a stent or conduit delivery system to provide a bypass through the myocardium from the left ventricle into a coronary artery.
2. Description of the Related Art
Coronary arteries as well as other vessels frequently become clogged with plaque that at the very least impairs the efficiency of the heart""s pumping action and can lead to heart attack and death. One conventional treatment for clogged coronary or other arteries is a bypass operation wherein one or more venous segments are inserted between the aorta and the coronary artery. The inserted venous segments or transplants act as a bypass of the clogged portion of the coronary artery and thus provide for a free or unobstructed flow of blood to the heart.
Such coronary artery bypass surgery, however, is expensive, time-consuming and traumatic to the patient. Hospital stays subsequent to the surgery and convalescence are prolonged.
A new coronary artery bypass technique is disclosed in U.S. Pat. No. 5,429,144. That technique utilizes a stent made of a biocompatible material and comprises steps of moving the stent in a collapsed configuration through a blood vessel of a patient""s vascular system to the patient""s heart, inserting the stent in the patient""s myocardium, and upon disposition of the stent in the myocardium, expanding the stent from the collapsed configuration to a substantially tubular expanded configuration so that a blood flow path is formed at least partially through the myocardium.
One problem with tile coronary artery bypass method providing a stent through the myocardium of the heart is how to get the stent into the myocardium. U.S. Pat. No. 5,429,144 describes a percutaneous approach wherein the stent is brought to the myocardium through the patient""s vasculature on the distal end of a catheter, and advanced into the myocardium over a guidewire. One particular challenge is how to make an angled bend in the guidewire to puncture through the wall of the vessel and into the myocardium. This challenge is exacerbated when it is desired to penetrate the guidewire through the myocardium at an obtuse angle relative to the direction that the guidewire is advanced through the vasculature.
Another problem with this approach is that catheters delivering the guidewire, stent or other devices to be provided into the myocardium are conventionally guided to the puncture point through the blockage in the coronary artery. However, when the blockage is too large, a delivery catheter cannot access the desired insertion site.
In addition, it is often difficult to advance devices into the myocardium because of the traction and force necessary to push through the myocardium. This problem arises not only for delivery of the stent, but also for the delivery of dilation catheters used to expand the cross-section of the passageway through the myocardium, and other devices.
Accordingly, what is needed is a method and apparatus for delivering guidewires, stents and other devices into the myocardium. In particular, what is needed is a delivery system that can deliver these devices at an angled bend for transverse insertion into the myocardium. Moreover, what is needed is a delivery method and apparatus for advancing a delivery catheter to a puncture site in a coronary vessel when the blockage in the vessel is too large to permit passage of a catheter therethrough. What is also needed is a method and apparatus for advancement of a stent, dilation catheter or other device into and through the myocardium.
Briefly stated, the present invention addresses the above needs by providing various methods and apparatuses for delivering stents or conduits and other devices into the heart wall or myocardium of a patient. One preferred stent delivery system provides access to the insertion site in the myocardium by advancing a delivery catheter through a blockage in a coronary artery, or around the blockage through a coronary vein or through a channel or tunnel formed around the blockage. In one embodiment, once the distal end of the delivery catheter is adjacent the myocardium, an angled bend is created in the catheter by actuating expandable steering guides mounted to the catheter which cooperate with the walls of the blood vessel to cause the catheter to turn. Then, a guidewire is advanced through the delivery catheter and into the myocardium. In another embodiment, a tip-deflecting pull wire extends from the distal end of the delivery catheter which may be actuated to turn towards and then inserted into the myocardium. In another embodiment, an exit port facing the insertion site is provided within the catheter or a balloon mounted on the catheter so that a guide ire may be directed through a lumen and out the exit port into the myocardium. Once the guidewire punctures into the myocardium, the guidewire is anchored using barbs, balloons or other actuatable members to secure the guidewire to the myocardium. Subsequently, using a push-pull mechanism, stents and other medical devices can be advanced over the guidewire into the myocardium.
In one aspect of the present invention, a guidewire is delivered into the patient such that the proximal end of the guidewire extends out of the patient, while the distal end of the guidewire is positioned adjacent the heart wall. The distal end of the guidewire is inserted into the heart wall, and the guidewire is then anchored to the heart wall. An introducer catheter carrying a medical device is advanced over the guidewire to deliver the device into the heart wall.
In another aspect of the present invention, a method for delivering a conduit into a heart wall to bypass a blockage formed in a coronary artery is provided. A channel is created from a position proximal to the blockage in the coronary artery to a position distal to the blockage in the coronary artery. A guidewire is advanced through the channel until a distal end of the guidewire is adjacent the heart wall. The guidewire is inserted into the heart wall, and a conduit is advanced over the guidewire into the heart wall.
In another aspect of the present invention, a bypass around a blockage in a blood vessel is formed by delivering a guidewire along a pathway from a location in the blood vessel proximal to the blockage to a location in the blood vessel distal to the blockage. A channel is created along the pathway formed by the guidewire. This pathway may preferably be created either through the heart wall or through the pericardial space. The channel may be dilated and shunted along the pathway defined by the guidewire.
In another aspect of the present invention, a method is provided for creating a bypass around a blockage in a coronary artery, adjacent a heart wall. A needle is inserted into a patient into the heart wall, the needle having a lumen extending therethrough. The needle is advanced through the heart wall and into the coronary artery distal to the blockage. A guidewire is advanced through the lumen in the needle, the guidewire once advanced extending through the coronary artery proximal to the blockage, through the heart wall, and into the coronary artery distal to the blockage. The needle is removed from the patient while leaving the guidewire in place. A shunt is advanced over the guidewire, the shunt once advanced having a distal end in the coronary artery distal to the blockage.
In another aspect of the present invention, a method is provided for creating a bypass through the heart wall of a patient to bypass a blockage formed in a coronary artery. A first tunnel is created through the heart wall having a proximal end and a distal end. The proximal end of the tunnel opens into the coronary artery proximal to the blockage. The distal end of the tunnel is positioned within the heart wall. A second tunnel is created through the heart wall, the second tunnel having a first branch extending from the distal end of the first tunnel and opening into the coronary artery at a position distal to the blockage. A second branch of the second tunnel extends from the distal end of the first channel and opens into a heart chamber. A conduit is disposed in the second tunnel to provide a passageway therethrough.
In another aspect of the present invention, a delivery catheter is provided. This delivery catheter comprises an elongate tubular body having a proximal end and a distal end and a lumen extending therethrough. A first steering member is mounted on the distal end of the tubular body, and a second steering member is mounted on the distal end of the tubular body at a position distal to that of the anchoring member.
In another aspect of the present invention, a method for turning a distal end of a catheter within a body lumen is provided. The catheter comprises an elongate tubular body having a proximal end and a distal end. An anchoring member mounted to the distal end is actuated to secure the catheter against the body lumen. A steering member is mounted to the distal end of the of the guidewire at a position distal to that of the anchoring member. When actuated, the steering member cooperates with the body lumen to turn the distal end of the catheter.
In another aspect of the present invention, a method is provided for delivering a medical device to a delivery site within a patient. This method comprises providing a delivery catheter having a proximal end and a distal end and a lumen extending therethrough into a body lumen of the patient. The delivery catheter is secured within the body lumen. The distal end of the catheter is turned by actuating a steering member mounted on the distal end of the catheter which pushes off against a wall of the body lumen. The medical device is advanced through the lumen of the delivery catheter and out the distal end.
In another aspect of the present invention, a method for delivering a conduit into the heart wall of a patient is provided. A delivery catheter is advanced into the vasculature of the patient, the delivery catheter having a proximal end and a distal end and a lumen extending therethrough, until the distal end is adjacent the heart wall. A pull wire extending from the distal end of the delivery catheter is actuated to turn the pull wire toward the heart wall. The pull wire is advanced from the distal end of the delivery catheter into the heart wall. The conduit is delivered over the pull wire into the heart wall.
In another aspect of the present invention, a method for delivering a conduit into the heart wall of a patient is provided. A delivery catheter is advanced into the vasculature of the patient, the catheter having a proximal end and a distal end and a lumen extending from the proximal end to a side port near the distal end, until the side port faces the heart wall. A guidewire having a proximal end and a distal end is inserted into the lumen. The distal end of the guidewire is advanced through the lumen and out the side port. The guidewire advances into the heart wall, and the conduit is delivered over the guidewire into the heart wall.
In another aspect of the present invention, a method for delivering a conduit into the heart wall of a patient is provided. A delivery catheter is advanced into the vasculature of a patient, the catheter having a proximal end and a distal end, until the distal end is adjacent the heart wall. An anchoring member mounted on the distal end of the catheter is expanded to secure the delivery catheter within the vasculature. A guidewire having a proximal end and a distal end is inserted through a lumen in the expanded anchoring member, the lumen extending from a proximal end of the anchoring member to a side port facing the heart wall, so that the distal end of the guidewire exits through the side port. The guidewire advances into the heart wall, and the conduit is advanced over the guidewire into the heart wall.
In another aspect of the present invention, a delivery catheter is provided. The catheter comprises an elongate body having a proximal end and a distal end. An expandable member is mounted on the distal end of the tubular body, the expandable member having a proximal end and a distal end and an exterior surface. A guide lumen extends from the proximal end of the balloon to a side port on the exterior surface of the expandable member for directing a medical device therethrough.
In another aspect of the present invention, a delivery catheter is provided comprising an elongate body having a proximal end and a distal end defining a generally longitudinally axis therebetween. A guidewire lumen extends at least partially between the proximal end and the distal end of the elongate body, having a proximal end and a distal end. An exit port at the distal end of the guidewire lumen creates a curve of between about 0 and a180 degrees relative to the longitudinal axis of the elongate body for directing a guidewire out of the lumen. In one embodiment, the exit port is a side port formed proximal to the distal end of the elongate body. In another embodiment, the exit port is at the distal end of the elongate body, and comprises a narrowing passageway between the guidewire lumen and the exit port.
In another aspect of the present invention, a method for treating an aneurysm is provided. A catheter having a proximal end and a distal end is advanced to the site of the aneurysm. An expandable member mounted on the distal end of the catheter is actuated to substantially enclose the aneurysm. An embolic element is inserted into the aneurysm.
In another aspect of the present invention, an assembly for delivering a medical device into the heart wall of a patient is provided. The assembly comprises an insertion tube having a proximal end and a distal end and a delivery channel extending therethrough. A tubular member is provided having a proximal end and a distal end and a lumen extending therethrough, the tubular member having a distal portion provided with an internal spring bias tending to form the distal portion into an arcuate configuration in the absence of an external straightening force on the distal portion. The tubular member is longitudinally slidable in the delivery channel. The distal portion may be alternately maintained in a relatively straightened configuration in the distal end of the channel and moved outside of the channel to assume the arcuate configuration. A guidewire is longitudinally slidable within the lumen of the tubular member.
In another aspect of the present invention, a method is provided for delivering a guidewire at an angle into a desired insertion site in the body. The method comprises delivering an insertion tube into the vasculature of a patient, the insertion tube having a delivery channel extending therethrough and once delivered having a proximal end located outside of the patient and a distal end located adjacent a desired insertion site. A delivery catheter is delivered through the delivery channel, the delivery catheter having a guidewire lumen extending therethrough. The delivery catheter once delivered has a proximal end outside of the patient and a distal end within the delivery channel. The distal end of the delivery catheter is ejected out of the delivery channel at the distal end of the insertion tube. The ejection of the delivery catheter from the delivery channel causes the distal end of the delivery catheter to turn toward the insertion site. A guidewire is advanced through the guidewire lumen into the insertion site.
In another aspect of the present invention, a method is provided for delivering a guidewire into the heart wall. A guidewire is inserted into a lumen of a delivery catheter, the guidewire having a proximal section and a distal section. The distal section of the guidewire is folded back over the proximal section while inside the delivery catheter lumen. The delivery catheter is delivered into a patient, the delivery catheter once delivered having a proximal end outside of the patient and a distal end adjacent a desired insertion site in the myocardium. The distal section of the guidewire is ejected out of the lumen of the delivery catheter at its distal end. The guidewire is pulled proximally such that the distal section punctures into the heart wall at an obtuse angle relative to the direction that the guidewire is ejected out of the lumen of the delivery catheter at its distal end.
In another aspect of the present invention, a method for delivering a guidewire into an insertion site in the body is provided. A delivery catheter having a proximal end and a distal end and a lumen extending therethrough is advanced into the body. The distal end of the delivery catheter once advanced is located adjacent the insertion site. The distal end of the delivery catheter is turned toward the insertion site. A guidewire is advanced through the lumen in the delivery catheter from the proximal end toward the distal end. The guidewire is guided out the distal end and into the insertion site through a narrowing passageway formed in the lumen.
In another aspect of the present invention, a method for delivering a medical device into a body tissue of a patient is provided. The method comprises inserting a guidewire having a proximal end and a distal end into the myocardium from a coronary blood vessel. The guidewire is anchored to the body tissue, and the medical device is pushed over the guidewire into the body tissue. The proximal end of the guidewire is correspondingly pulled proximally while the medical device is pushed distally in order to assist advancing the medical device through the body tissue.
In another aspect of the present invention, a delivery system for directing medical treatment at least partially into a heart wall is provided. The delivery system comprises a guidewire having a proximal end and a distal end, means for turning the distal end of the guidewire toward the heart wall, means for anchoring the guidewire to the heart wall, and a catheter carrying the medical treatment having a lumen extending therethrough for receiving the guidewire and advancing the catheter into the heart wall.
In another aspect of the present invention, a method for delivering a conduit into the heart wall of a patient to bypass a blockage formed in a coronary artery is provided. The method comprises advancing a catheter having a proximal end and a distal end and a lumen extending at least partially therethrough from the proximal end to a distal opening through the coronary artery of the patient until the distal opening is past the blockage. The catheter is turned so that the distal opening faces the heart wall. A wire having a proximal end and a distal end is extended through the distal opening such that the distal end punctures into the heart wall. The distal end of the wire is anchored to the heart wall. A dilation catheter is delivered over the wire, the catheter carrying a dilation balloon on a distal end thereof, until the balloon is within the heart wall. The dilation balloon is inflated to create an opening in the heart wall. The dilation balloon is then deflated and the dilation catheter removed from the wire. A conduit introducer catheter is delivered over the wire, the conduit introducer catheter carrying a conduit on a distal end thereof, until the conduit is located within the opening in the heart wall. The conduit is deployed within the opening in the myocardium.
In another aspect of the present invention, a method for delivering medical treatment into the heart wall of a patient is provided. A tubular wire is delivered into the patient, the wire having a lumen extending therethrough. The wire once delivered has a proximal end extending out of the patient and a distal end positioned adjacent the heart wall. Means for turning the distal end of the wire towards the heart wall are provided. Then, the distal end of the wire is inserted into the heart wall. Medical treatment is delivered through the lumen in the wire into the heart wall.